The incidence of ductal carcinoma in situ of the breast (DCIS) has risen dramatically among women in the United States since the early 1980's. Survival for DCIS is very high regardless of the type of surgical treatment and, for patients with favorable histopathology, the risk of local recurrence post-lumpectomy is very low. There are, however, large variations in the surgical management of DCIS patients. Although many women with DCIS appear to be ideal candidates for breast conserving therapy, mastectomy rates for this particular form of breast cancer remain high. This has led to concerns about "over treatment" among clinicians and patient advocacy groups alike. Unfortunately, we do not know enough about the factors that influence breast cancer surgery choice and the processes by which complex treatment decisions are made to fully inform these debates. Furthermore, we have little information about outcomes such as patient satisfaction or subsequent quality of life for women with DCIS, and to what extent these important outcomes may differ between women with DCIS and those with invasive breast cancer. We propose a multi-center population-based study to examine a broad array of determinants (external influences, clinical factors, predisposing/enabling factors, and patient knowledge and attitudinal factors) that are associated with three outcomes for women recently diagnosed with breast cancer: 1) surgical treatment choice (mastectomy vs lumpectomy with or without radiation); 2) short-term patient satisfaction with the treatment decision and the treatment-making process; and 3) health-related quality of life. The study will be conducted using a population-based sample of breast cancer patients in three racially and socioeconomically diverse urban areas in the United States (Detroit, Los Angeles and Atlanta). An initial sample of 2900 women recently diagnosed will be selected prospectively from three Surveillance, Epidemiology and End Results (SEER) catchment areas over a 15-month period using a rapid case ascertainment process. This sample will be stratified by level of disease (1450 women with DCIS and 1450 with invasive disease), and we will oversample African-American women. Eligible women consenting to be in the study will receive a standardized survey questionnaire in the mail for self-administration. Based on our pilot experience in the Detroit SEER site, we expect that approximately 75 percent of patients eligible for the study will complete questionnaires (N=l880).